Flash-boiler system.



No. 726,442. PATENTED APR. 28, lbs.

A. F. MACDONALD.

FLASH BOILER SYSTEM.

APPLICATION FILED PEB.16, 1903.

N0 MODEL. 2 SHEETS-SHEET 1.

Witnesses: Inventor:

A Jqlexancler- YTM?cdonald,

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PATENTED APR. 28, 1903'.

A. F. MACDONALD. FLASH BOILER SYSTEM.

.APPLIOATION FILED FEB.16, 1903.

2 SHEETS-SHEET 2.

N0 MODEL.

Pm @m mm Inventor: Jqlexand y M Witnesses PFTMacdonald, 9i may YH: upnms va'rzns co. Pnonnn'no.v WASHINGTON. u

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ALEXANDER F. MACDONALD, OF SOHENEOTADY, NEW YORK, ASSIGNOR TO ELII-IU THOMSON, OF Sl/VAMPSCOTT, MASSACHUSETTS.

FLASH BOlLER SYSTEM.

SPECIFICATION forming part of Letters Patent No. 726,442, dated April 28, 1903.

Application filed February 16, 1903. Serial No. 143,533. (No model.) V

T (LZZ whom it may concern:

Be it known that I, ALEXANDER F. MAO- DONALD, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented cer tain new and useful Improvements in Means for Regulating Flash-Boiler Systems,of which the following is a specification.

In order to obtain the highest efficiency in a flash-boiler system with a minimum expenditure of fuel and water, the supplies of fuel to the burner and water to the boiler should be increased or decreased as the demand for steam changes, and the variations in the amounts of fuel and water supplied should take place simultaneously with the variation in demand for vapor energy and in substantially the same degree.

My invention has for its object to provide animproved regulating means for flash-boiler systems whereby the amounts of fuel and water can be accurately regulated to meet the varying conditions of service.

For a consideration of what I believe to be 2 5 novel andmy invention attention is called to the description and claims appended thereto.

In the accompanying drawings, which represent certain embodiments of my invention, Figure 1 is a diagrammatic view of a flash- 0 boiler system. Fig. 2 is a slight modification showing a hand-regulator, Fig. 3 is a further modification wherein the action of the automatic regulator is modified by a handregulator. Fig. 4: is a further modification wherein the by-pass valves are actuated by the engine-pressure, and Fig. 5 is a modifica tion wherein the by-pass regulators are differentially arranged.

In carrying out my invention fuel and water pumps are provided whose deliveries bear a certain relation to each other at all times, whereby the proper amount of heat is furnished to convert a given amount of water or other liquid into vapor at a certain temperature. In order to regulate the deliveries of the pumps in accordance with the demand for vapor energy, a by-pass valve or regulator is provided for each pump, which regulators are simultaneously manipulated or adjusted either by hand or automatically in accordance with the demand for vapor energy. It has been proposed heretofore to provide a pump with a relief-valve, so that the excess fluid could return to the snpply'tank; but in this case the valve was provided with a spring which ,only permitted the valve to open after Hence the load on the engine driving the pumps is reduced to a minimum.

I may operate the by-pass regulators in a number of different ways, depending upon the conditions of service. In certain instances it is best to employ a thermostat, and prefer- 7o ably one that is acted upon by the fire-gases as distinguished from a thermostat operated by changes in temperature of the vapor. By depending upon a thermostat acted upon by changes in temperature of the flue-gases any variation is instantly detected and compensated for, whereas with a thermostat acted upon by steam there must of necessity be a slight lag, owing to the metal interposed between the flue-gases and the vapor.

I may control the by-pass Valves or regulators by hand in certain cases.

1 represents a boiler-casing, in which is mounted a flash-boiler 2, composed of a number of steel tubes wound or bent into any suitable shape. Situated below the boiler-tubes is a fire-chamber, inwhich is located a hydrocarbon -burner 3 of the jet type. Situated above the boiler-tubes and acted upon by the fire-gases isa vapor-tension thermostat 4, .90 which may with advantage contain kerosene, as kerosene has a high boiling-point. A thermostat thus formed is powerful in its action and quick to respond to variations in tem-. perature of the flue-gases. Water is supplied to the boiler by the pump 5 and fuel to the burner by the pump 6. The deliveries of these pumps bear a definite relation to each other at all times in order that the vaporgenerated by the boiler shall be produced under the most economical conditions. The two pump-pistons are rigidly connected together and are driven by an eccentric 7, that is belted or otherwise connected with an engine 8.

The eccentric can with advantage be placed on the driving-axle of a vehicle when the system is used for vehicle regulation. The eccentric-rod is provided with a cross-head 9, which is connected by alink to the pumppistons. Steam is admitted to the engine by the throttle-valve l0, and the exhaust therefrom is discharged into a muiiier 11, situated at the top of theboiler. This muffler or chamber communicates with the downdraft-flue 12. The boiler is also provided with a fineopening 13, by means of which the fire-gases escape under natural draft. When the exhaust steam is being discharged into the downwardly-opening flue 12, all or substantially all of the flue-gases are discharged therefrom, the flue-opening 13 being practically shunted. Water for the boiler is contained in a supply-tank 14, and the waterpump is provided with a suction-Valve 15 and a delivery-valve 16. In circuit with the delivery-pipe 17 of the water-pu mp is a by-pass regulator, which is acted upon by the diaphragm 19, the latter being connected to the vapor-tension thermostat 4. Connected to the by-pass regulator 18 is a pipe 20, by means of which the excess water or other liquid is returned to the supply-tank. It is to be noted that the load on the pump is decreased as soon as the by-pass valve is opened, which is one of the distinguishing features of my invention. Everythingwhich decreasestheload on the engine tends, of course, to increase the efficiency of the system as a whole.

Fuel for the system is supplied by the tank 21, which may with advantage be under a small initial pressure for the purpose of starting. The fuel-pump is connected thereto and is provided with a suction-valve 22 and a delivery-valve 23. In circuit with the pipe 24, which conveys fuel to the burner, is a bypass regulator 25, which comprises a balanced piston 26, that is arranged to cover and uncover the port 27, the latter being in communication with the tank by the pipe 28. In order to actuate the piston-valve 26, a diaphragm-regulator 29 is provided, which is acted upon by the pressure in the vapor-tern sion thermostat 4. The valve-stem is connected by a link to the bell-crank levers 30, and the latter is urged in one direction by a diaphragm and in the opposite direction by a spring 31. When the piston-valve 26 is in the position shown, all the fuel delivered by the pump will pass through the pipe 21 into the burner. When the pressure on the diaphragm increases, the piston-valve is forced downward and more or less of the fuel will be by-passed through the port 27 and pipe 28 to the tank, the balance going to the burner, as before. It is desirable to make the port 27 relatively long and narrow, so that considerable movement of the piston-valve is required to by-pass all or substantially all of the fuel from the pump. The construction and arrangement of the by-pass regulator 18 for the water-pump are the same as those described in connection with the fuel-pump. It is evident that when the temperature of the fire-gases increases abnormally the pressure created within the vapor-tension thermostat 4 will be exerted on the diaphragms 19 and 29 in a manner to cause the pistons to be forced downward, and thus permit a certain amount of fuel and water to be by-passed to the supply-tanks. Conversely, when the pressure in the thermostat falls the springs 31 pull the pistons in the by-pass regulator upward, so that they cover the ports leading to the pipes 20 and 28. By-decreasing the load on both pumps under certain conditions it is evident that the load on the engine is considerably decreased.

Referring to Fig. 2, I have shown a slight modification of theinvention wherein a handactuated device is employed to control the by-pass valves or regulators 18 and 25. In this case 5 and 6 represent the water and fuel pumps, as before. These are driven by an eccentric 7, which is placed on a shaft or axle 35. Included in the driving connection is a flexible connection 86, comprising a number of elastic or rubber buffers. These buffers are placed between the heads 37 and 38. The head 37 is connected to the eccentric-rod, while the head 38 is connected to the pistons of the pumps. The advantage of a construction of this kind resides in the fact that if for any reason the pressure on the system tends to exceed a predetermined maximum the buffers will be compressed to a greater or less extent and the stroke of the pumps will be correspondingly decreased. In this manner all danger due to abnormal conditions owing to carelessness on the part of the operator is prevented.

In order to adjust the position of the pistons in the by-pass regulators 18 and 25, a segmental gear 39 is suitably pivoted and connected by a link 40 with the bell-crank levers 30, the latter being connected by links to the regulator-pistons. Motion is imparted to the segmental gear by a worm 41, which is provided with a suitable handle.

With a little experience the operator can readily adjust the by-pass valves or regulators to suit the conditions of service. In this connection a temperature-indicator may be employed, if desired.

In Fig. 3 is shown a slight modification wherein a single diaphragm 42 is employed to actuate the bell-crank levers 30, which are connected to the by-pass regulators.

In order to modify the action of the automatic by-pass regulators to suit the conditionsofservice,anextension-springor equivalent device 43 is provided, which is adjusted bya screw-threaded rod and nut 44. Ohviously as the tension on the spring 43 is varied the pressure on the diaphragm 42, which is necessary to move the pistons of the bypass regulators, is varied.

- In Fig. at I have shown my improved regulater in connection with a diaphragm that is teams actuated by the engine-pressure as distinguished from those systems utilizing the boiler-pressure. In flash-boiler systems the pressure may vary from practically nothing up to several hundred pounds. Hence it cannot be relied upon to actuate a regulator. It has been found. by test, however, that the pressure on the engine varies in proportion to the demand for heat energy. Hence a regulator which is acted upon by the enginepressure can be relied upon to vary the admission of fuel and Water to the burner and boiler, respectively. In this figure, 2 represents the flash-boiler, 8 the engine, and 10 the throttle-valve. Between the throttle and the engine is a pipe 4-5, containing a cut-off valve 46. Under ordinary running conditions this valve is open andavhatever pressure there is on the engine is exerted on the diaphragm 42. This diaphragm can be employed to operate both the bypass regulaf tors for the fuel and Water systems. In cases where a boiler is employed having considerable storing or holding capacity for steam its pressure may be depended upon to actuate the diaphragm 42. In this case a connection, such as -17, would extend from a point between the hoiler and the throttle-valve 10 to the diaphragm 4-2 In this case the valve 46 would be closed.

Referring to 5, I have shown a differential system of regulation which possesses certain advantages in that changes of temperature can be compensated for more quickly than Where the supplies of fuel and water are increased or decreased simultaneously. To state the matter in a different vvay, When the boiler is too hot instead of cutting down the fuel alone the supply of fuel is out down and the supply of Water is increased, in this manner applying What might be said to be two remedies to compensate for the abnormal condition. The regulators 18 and 25 are constructed in the same manner as described in connection with Fig. 1, the difference being, however, that the bell-crank levers 30 instead of being similarly set, so as to produce corresponding movements of the piston-valve 26, are set oppositely, so as to produce dissimilar movements of the pistons. Assuming, for example, that the actuating-rod or connection 40 is moved to the left in the direction of the arrow under increased pressure in the thermostat, the piston of the regulator 18 will move downward, and uncover the port 27, thus decreasing the fuel-supply, While the piston in the regulator 25 Will move upward and cover the port 48 to a greater or less extent, thus increasing the Water-supply to a certain extent. These piston-valves are preferably, although not necessarily, set so that When the diaphragm or other actuating device is set at its normal condition the bypass ports 27 and -l8 are uncovered to aslight extent. Under this condition the necessary amount of water will be delivered by the Water-pump 5 and the necessary amount of will be delivered by the fuel-pump 6 to supply the maximum needs of the'boiler and burner, respectively. When the position of the valves is modified with respect to the ports 27 and 48, the amount of fuel and water delivered by the pumps to the burner and boiler will be varied. In this case the capacities of the pumps \villbe slightly greater than those previonsly described to compensate for the normal opening to the ports 27 and 48. The regulators are intended to be adjusted once for all, after which they will vary the supplies of fuel and Water in the proper manner; but I may use an adjusting means such as described in connection with the previous figures.

In accordance With the provisions of the patent statutes I have described the principle of my invention, together with the apparatus which I nowconsider to represent the best embodiment thereof 3 but I desire to have it understood that the apparatus shown is merely illustrative and that the invention can be carried out by other means.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In combination, a boiler, a means for supplying liquid thereto in accordance with the demand for vapor energy, a burner, a means for supplying fuel to the burner in accordance with the demand for heat, separate bypass valves for each of said means, and a device for simultaneously and ing the valves.

2. In combination, a boiler, a burner, a pump for supplying liquid to the boiler, a pump for supplying fuel to the burner, a bypass valve in the circuit of each of the pumps, and a means for simultaneously and gradually adjusting the by-pass valves.

3. In combination, aboiler,aburner, pumps for supplying liquid to the boiler and fuel to the burner, a means for imparting simultaneous movements to the pumps, by-pass valves for the pumps, and automatic means for actuating the valves ina manner to gradually vary the deliveries of the pumps.

4.. In combination, a boiler,a burner, pumps for supplying liquid to the boiler and fuel to the burner, 21. means for imparting simultaneous movements to the pumps, by-pass valves for the pumps, and a pressure device acting on thevalves for causing corresponding and gradual variations in the liquid and fuel supplies.

5. In combination,a boiler, aburner,pumps for supplying liquid to the boiler and fuel to the burner, a means for imparting simultaneous movements to the pumps, by-pass valves for the pumps, automatic means for actuating the valves in a manner to gradually vary the deliveries of the pumps, and a device for adjusting the effect of said means.

6. In co1nbination,a boiler, a burner,pumps for supplying liquid to the boiler and fuel to the burger, driving means for the pumps, bya ssir'ailves for regulating the deliveries, and

gradually mova thermostatic device for simultaneously in accordance with the changes in boiler tem opening and closing the by-pass valves. perature. 1d

7. In combination, a boiler for supplying In witness whereof Ihave hereunto set my superheated vapor, a burner, variable-stroke hand this 12th day of February, 1903.

pumps for supplying liquid to the boiler and ALEXANDER F. MACDONALD. fuel to the burner, a by-pass valve for each Witnesses: of the pumps, and a thermostatic regulator DUGALD MOK. MCKILLOP,

for changing the position of the by-pass valves JOHN A. MCMANUS. 

